Silver-foot

Idril was the daughter of Turgon of the Noldor and Elenwë of the Vanyar, and she had the golden hair of her mother's kin. She was famed for the paleness of her skin, and as it was her custom to walk or dance in Gondolin barefoot, she became known as IdrilCelebrindal, or Idril the Silver-foot. The choice of the word 'silver' here shows just how pale her skin must have been, though perhaps it was also chosen as a play on her given name, Idril, which incorporates the Elvishitaril, 'sparkle, glint', and so already connected her with the gleam of metal.